Next question. According to this book.
the L20B has these cast bracket mounted to the bottom back end of the block to bolt to the bell housing of the transmission.
My engine didn’t have it when I bought it. I guess the pervious owner got rid of them.
Do I need them?

Time to buy more parts and wanted to get some input first. Remember I’m fitting this L20B in my ‘68 520. I know there will be cutting and welding but was trying to stay away from cutting the firewall. So I need to get a water pump and a radiator. What do I buy? Do I go stock, ‘78 620 water pump with clutch fan (that was original to the engine). I don’t see any original style radiators on eBay, only aluminum ones. Would that combo be too deep and not fit. I heard, and it looks like it’s going to be tight. Also, the ‘68 520 face has four head lights with a space of 23 inches between where the radiator needs to go. What about an L16 water pump with a fixed fan? Will that save space? Any different options on the radiator? I’m looking forward to reading anybody’s thoughts. Thanks

yes. It’s in good working order. Moves freely. So it’s a bi-metallic spring. Makes sense. When cold, it’s short and closes the trap pushing air to the heat sink. When hot the spring metal expands allowing the gasses to easily open it. When the engine is off again, the metal spring will cool and shrink closing it back off again for the next start. Sounds good.
Now is there much harm in disabling it? I’m not planning on doing a lot of cold driving. Or just leave it alone. It’s still working after 40 years. It will keep working. What do you think.

A new question for you all today.
The spring exhaust flap in the exhaust manifold. How does it work? My guess is that at low rpms the flap is in the position seen in the photo above directing hot exhaust gasses up towards the heating plate sandwiched between the exhaust and intake manifold. When the rpms go up, the exhaust gasses increase in pressure pushing the flap open allowing the gasses to flow more freely through the rest of the exhaust system. When the rpms come back down, the spring and lack of exhaust gas pressure allows the flap to close directing more heat to the heating plate. ??? Am I right?
so is the flap needed? I don’t plan on doing much cold weather driving. Heard something along the lines was what the heating plate was for. The flap looks very restrictive. Can I just do away with it or position the flap so it is always open (least amount of restriction of gasses flowing through the exhaust system and out?
thanks

I need some carb knowledge passed along to me if anyone is willing. The carb that came with the L20B looks completely shot. Not worth the effort to rebuild it. I’ve found a Weber carb that fits the engine but then I got to thinking about the carb on my j13 that will be coming out of my 520 for the L20B to go in. Can that carb be used on the L20B?
The carb on the j13 is a Nikki and seems to be in good condition. Will it fit the L20B? Will it work on the L20B? Any thoughts? Thanks

Got some progress done. The 5 speed trans is all rebuilt. The L20B has been to the machine shop and bored over for .40 pistons. The bottom end has been assembled. Now I’m sourcing my replacement accessories.

From what I’ve read, my ‘77 ish FS5W71B trans has Borg Warner synchros on gears 1-4 and Servo type synchro on 5th gear. I need one of these “Servo” type synchros. Mine’s chewed up and need a new one. I found a website, datnissparts.com, that states the “X Steel Synchronizer Ring” is the same for roadster 5th gear in fs5c71a, fs5c71b, and some FS5W71B overdrives found in the 620. But... is no longer available from them. I see the servo ring on Datsunparts.com but it’s $150 (for a roadster). Is there any other options or places to purchase?

Ok. Some more questions - I need some help finding where to get some replacement parts for the transmission. I was able to find the seals, o-rings, and oil gutter from Nissan. I can’t find the tail house bushing in picture 1.
and I can’t find this synchronizer ring (Part 18) for the overdrive main gear seen in the pictures below.
Any ideas where to source these parts?

Does anybody know how to remove the “dog leg” off of the shift rail from a ‘77 FS5W71B? I saw a YouTube video where the trans the guy was working on had a bolt hole in the rear of the housing where he could reach in and knock the pin out of the dog leg. My tail housing doesn’t have that hole. I removed the nut but the pin won’t budge and I can’t get an angle on it to knock it out. Any ideas?